


fingertip to fingertip

by crocustongues



Category: Haikyuu!!
Genre: Bokuto & Hinata & Kenma all appear in the background, Canon Compliant, Gen, M/M, Pre-Slash, spoilers for the national's arc
Language: English
Status: Completed
Published: 2020-02-23
Updated: 2020-02-23
Packaged: 2021-02-28 03:26:55
Rating: General Audiences
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 1,183
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/22867075
Author URL: https://archiveofourown.org/users/crocustongues/pseuds/crocustongues
Summary: following growth through kuroo's eyes; a study in waiting and a series of texts.
Relationships: Kuroo Tetsurou & Tsukishima Kei
Comments: 2
Kudos: 20





	fingertip to fingertip

**Author's Note:**

  * For [jercydee](https://archiveofourown.org/users/jercydee/gifts).



> hello, i can offer only the most ardent of apologies for this scandalously late gift but i hope you enjoy! no prior knowledge of science is required & no physics grads were harmed in the making of this fic.

**The time evolution of wave functions is deterministic in the sense that—given a wave function at an initial time—it makes a definite prediction of what the wave function will be at any later time.**

When Kuroo turns seventeen, weighed down by the world in a way only teenagers with a sense of responsibility and the talent for feigning an air of nonchalance are, he finds himself an unwilling disciple.

He’s not a very good student, in the way one needs to be when generally in pursuit of a hobby that deals with something as high stakes as sports. Kuroo doesn’t really understand it—and he suspects Bokuto understands even less—but he’s willing to give the kid pointers. He calls it kindness, but there’s an excitement that spreads in his gut when he thinks about how he’ll do anything to make sure their teams find themselves face to face, tangled in an inevitability.

He meets this inevitability and the first and most striking memory he has is how he doesn’t like that Tsukishima is taller than him. He doesn’t let that show, of course, but it does grate on his nerves when the kid calls him _senpai_ but looks like he doesn’t mean it. He tries not to think about how Tsukishima has his own issues, from the general look of things. Kuroo’s had his own share of them back in the day.

They play ball until they drop and then they play some more. It’s unfairly warm. Between the squeaks of sneakers on the polished volleyball court and Hinata’s wails of pure amazement, Kuroo finds himself watching Tsukishima’s posture and strategy. He’s fast and he’s clever but he’s still only in his first year. So easy to fool and with a long way to go. Kuroo smiles at that and catches himself just in time to turn it into a frown and tells Tsukishima to bend forward a bit when he’s blocking.

He tells them all they played well—just shy of eking out a tear and telling them how proud he is of their stellar improvement—when Tsukishima stops them short.

 _That's the moment you’re hooked on volleyball!_ Bokuto had explained, with that manic glint in his eyes. Kuoo hadn’t ever stopped to wonder why he loves what he loves until Tsukishima questions it. He makes eye-contact with vivisection.

It really feels unfairly warm.

* * *

****

**Wave functions change as time progresses.**

Kuroo receives the good news from Kenma who shows him Hinata’s enthusiastic text announcing that Karasuno made it past the qualifiers. Two hours later, he receives a text of his own.

> _Made it to nationals. Thanks for your help, Senpai._

Kuroo’s heart lurches in his chest and he types out a reply, quick as heartbeat.

< _good to hear it. next time we crush u._

> _Hahahaha._

Caught between surprise and curiosity, Kuroo squints at the text. Tsukishima Kei is potentially diabolical.

< _heard u blocked good old ushiwaka. proud of u._

Surprisingly, this continues. Kuroo hears from Tsukishima fairly often, answering questions that mostly relate to blocking pointers. Sometimes, in the dead of night, Kuroo works up the courage to ask questions of his own. _What’s your favourite colour? Can you cook? Do you like math more, or science?_

He’ll work up to substantial courage one day.

Two Wednesdays before the Spring Tournament, Kuroo finds an unexpected text that sets him surfing on waves of bewildered delight.

> _What’s your favourite colour?_  
> _Hinata’s asking, by the way._

Kuroo ponders this over even though he has his responses ready; his favourite colour has always been red, rich and deep. And if Hinata really wanted to, for some godforsaken reason, know what Kuroo’s favourite colour was, he could’ve asked the question himself.

He replies with one of those and finishes tying his laces with an uncharacteristic smile and a flourish, ready to take on the world.

* * *

****

**During a measurement, on the other hand, the change of the initial wave function into another, later wave function is not deterministic, it is unpredictable.**

The next time Kuroo lays his eyes on Tsukishima Kei, it’s on the infamous orange court of fate. It’s evident Tsukishima has grown, both in prowess and in his love for the game. It makes Kuroo a tiny bit proud that he played a hand in every time his spikes get blocked.

The game proceeds, hearts pressing in their throats and determination bleeding in with sweat across the two halves of the court. After all said and done, Kuroo thinks fondly, bittersweet and unbearably nostalgic over the final dig, the final set, the final spike of his high school volleyball career. All said and done, in retrospect, he was glad it was Karasuno. That it was Tsukishima Kei to supercede him.

They stand off the courts, just next to the entrance to the locker rooms where they would change and sit in the bleachers for the next match, and Kuroo can see Tsukishima from the corner of his eyes, huddled with the rest of his teammates.

Hindsight is 20/20 and Kuroo’s never really needed glasses, so he marks this down as a mundane miracle that he remembers best. Kenma’s telling him (in not so many words) that this has probably been the best time in his life. He tears up a bit at that, and he’s blinking them back when he feels the air shift, just imperceptibly so. Kenma excuses himself to Hinata’s side, smiling softly to himself.

“Kuroo-san.” And here it comes.

“Good game,” Kuroo says, sincerely. He almost blurts out how he’s been keeping up with their progress, how he’s kept an eye on Tsukishima’s blocking stats, how he’s asked Lev if Tsukishima got taller in sheer incredulity.

“Good game,” Tsukishima parrots back, but for a change this, too, mirrors Kuroo’s sincerity. “I just wanted to say, I mean, I felt it was _necessary_ —” Tsukishima stops, smile sliding right off his face. His ears looked red hot. Far too early in the Spring to feel this unfairly warm.

Kuroo waits, his breath stuck between his tongue and his teeth.

“Thanks,” Tsukishima concludes after a beat of silence, in the smallest voice Kuroo had ever heard.

“Aw, is Tsukki turning emotional on me, hmm?” Kuroo smiles, laughter bubbling in his throat at the stupid serendipities the universe has flung at him thus far.

Tsukishima snorts, an overtly carefree sound. "Say, Kuroo-san.”

“Hm?”

“You gonna continue to help me out?”

Kuroo is, understandably, shocked beyond speech. But by virtue of being Kuroo Tetsurou and having the air of someone who’s got a lot more in control than he actually does, he says, “Of course. Can’t leave my protégé without some tricks to pull while I’m gone.”

“Then—” He’s interrupted by their captain, who holds their respect in an iron fist, regardless of how teary-eyed he looks.

“I’ll message you,” Tsukishima says eventually, slightly put out by the turn of events, and leaves before Kuroo can fully comprehend that.

And just because the universe likes to trip him up, he receives a text just then:

> _Since you never answered, what’s your favourite colour?_


End file.
